Link star formation theories and young cluster observations by studying the cluster dynamical evolution during the first million years.
The vast majority of stars is born in clusters or associations and is not isolated. It seems therefore fundamental to study the formation and evolution of stellar clusters if we want to understand the origin of young stars properties and thus constrain the theory of stellar formation. <br />• What are the initial conditions of cluster formation? <br />• What determines the distribution of stellar masses in clusters? <br />• Is there a universal mass function for stars, brown dwarfs, and giant planets produced in all clusters? <br />• How does the cluster environment affect the evolution of the statistical properties of young stars? <br />• Is the spatial mass-segregation primordial or the result of dynamical evolution? <br />To address this broad array of issues, the DESC project has been focusing on the cluster dynamical evolution during the first million years, in order to link the theories of stellar formation to the observations. <br />
To reach the above objectives, the DESC project combined i) multi-techniques observations of young clusters (<30 Myr) in order to fully characterize their statistical properties (IMF, binary properties, spatial distribution, kinematics), and ii) numerical simulations of the cluster dynamical evolution in order to trace back the initial conditions. Those that reproduce best the observations are then compared to model predictions of molecular cloud collapse in order to constrain the theories of stellar formation. A code combining the gas hydrodynamics to stellar interactions has been developed for this purpose.
On the observational side, emphasis was put on obtaining very precise proper motion measurements, as well as on the multidimensional analysis of color, magnitude, position and velocity of stars to compute their cluster membership probability and characterize their properties (mass distribution, multi-scale spatial structures, multiplicity).
In the framework of DESC, new methods to get very precise proper motion measurements, as well as statistical tools allowing the identification and characterization of cluster stars, and a numerical code combining the gas and stellar dynamics have been developed. These results prepare the scientific exploitation of the European Gaia space mission.
The project task on proper motion measurement and analysis led to the ERC “COSMIC-DANCE” (P.I. H. Bouy), and the new European collaborative project “StarFormMapper” is the extension of our research on the formation and evolution of stellar clusters.
The results obtained during the DESC project have been published in peer-reviewed journals (22 articles), and have been presented in international conferences (4 invited reviews, 8 contributed talks, 3 posters).
The 2015 PNPS international school (Evry Schatzman School) was on stellar clusters and has been organized and co-funded by the DESC project.
A 3-years postdoctoral contract has been funded by DESC and two PhD thesis linked to the project have started in 2011 and 2014.
The vast majority of stars are born in associations or clusters rather than in isolation. To understand the general rules that govern how stars form, it is therefore crucial to decode fully the formation and evolution of young stellar clusters. This is the main goal of this project, which will focus more specifically on the early dynamical evolution of stellar systems. To pursue these objectives, we propose to bring together theoretical and observational expertise drawn from two research groups well established in their respective field: the Stellar Formation group in Grenoble, which has a vast experience in young cluster observations; and the Galaxy team in Strasbourg, which has strong expertise in N-body numerical simulations. Thanks to the recruitment of an ANR postdoc, this project will allow to develop a new expertise on numerical simulation at LAOG that is essential to interpret the observations of young stellar clusters.
Madame Estelle MORAUX (UNIVERSITE GRENOBLE I [Joseph Fourier]) – email@example.com
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
LAOG UNIVERSITE GRENOBLE I [Joseph Fourier]
Help of the ANR 300,000 euros
Beginning and duration of the scientific project: - 48 Months